Hello, 

Taking online coaching for gate is good if you are staying far from the city or reputed institutes.

You have to be serious while you are taking online coaching and should concentrate a lot .

here are some online coaching links for the gate,

http://thegateacademy.com/

https://superprofs.com/

https://gateforum.com/

these are the top gate online coaching sites

You can refer our careers360 article on gate, I'm providing you the link below

https://engineering.careers360.com/exams/gate/articles

All The Best...

THANK YOU ....